Prepare the Crust
Preheat oven to 350°F (175°C) and line a muffin tin with cupcake liners.
Mix graham cracker crumbs, sugar, and melted butter in a bowl.
Press about 1 tablespoon of crust mixture into the bottom of each cupcake liner.
Bake for 5 minutes, then let cool.
Make the Cheesecake Batter
In a mixing bowl, beat cream cheese until smooth. Add sugar, cornstarch, sour cream, and vanilla.
Add eggs one at a time, mixing gently until just combined.
Divide batter into six bowls and color each with gel food coloring to create rainbow layers.
Layer the Cheesecakes
Start with purple batter and spoon a small amount into each muffin cup. Repeat with blue, green, yellow, orange, and red, carefully layering each color.
Bake at 325°F (163°C) for 18-20 minutes, or until set. Let cool completely.
Add the "Pot of Gold" Surprise
Use a small knife or spoon to create a tiny cavity in the center of each cheesecake.
Fill with gold sprinkles or edible gold pearls, then top with whipped cream.
Decorate and Serve
Sprinkle additional gold decorations on top. Add chocolate gold coins if desired.
Chill for at least 2 hours before serving.